Method for making composition fiber panels



Dec. 23, 1952 c, BLECKQ 2,622,302

METHOD FOR MAKING COMPOSITION FIBER PANELS Filed July 26, 1948 FIG-l. 20

25 IN V EN TOR.

CARL BLECKO [KW/W (r ATTORNEY Patented Dec. 23, 1952 aczzzsozv ironv COMPOSITION "BEER E Carl: Blecko, Preston, Wash, assignor. to. Rock.-

wood; Corporation; Issaquah, Wash, a corporate,

t ne izw shi tpp err1 a i gglm,194 en /1.1m 9,114.

3. Claims. (016 25-155) The present invention'relates to a method for producing fiber board;

"It-is an object of'the present invention to produce a fiber board comprising a cemented fiber body portion and a coating therefor containing plaster, wheat paste, sugar; bentonite, and'a'sbestos. V

It is a further object of the present invention to provide a method for producing a fiber board constructed and arranged'to' provide increased productivity in the production oftheboard It is a further object of'the present invention to provide a method of making fiber boards which comprises advancing a supply of fluid fibercement mix along an inclined path, providing working stations of different height along .said path providing a horizontal conveyor paralleling' said path, in which operators are provided at each station tofillforms and place them upon atop of a stack offorms advanced from a preceding station of less height.

I 'Other' objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the ae'ompanying drawings, wherein:

Figure 1 is a more or less diagrammaticside elevation of apparatus employedin the produc tion 'of fiber board.

"Figure 2 is a fragmentary .plan view of -the apparatus illustrated inFigure 1, and.

Figure 3 is a fragmentary'view partlyin section and partlybroken away of a stack of forms.

In accordance with thepresent invention, fiber board is produced by forming relatively long wood fibers, impregnatingthe fibers with salt by soaking them in a salt solution, thereafterdraining excessive ,moisture .from the fibers; thoroughly mixing the fibers with Portland cement, and finally placing the resulting fiuid mix in opentopped forms or molds. Special means'are provided to facilitate the operation of filling'the form's' and for assembling the filledforms in vertical stacks ortiers. After a predetermined number sip-arms have been assembled in vertically mer e-reation they are advanced into .la press. Theindiv idual' forms are so-shapedthat-when pressure is applied-thereto they will be compressed "together a predetermined amount so as to produce fiber boards of a uniform standard thickness. After pressure has been applied in a press the stack of forms is secured together and is allowed to set.

Subsequently, the boards are removed from the molds and are coated with a combination consisting of an aqueous mixture, the solid constituents of which are wheat paste, sugar, bentonite, and asbestos. This coatingmaterial-= is in the form of'a paste which is spread to=a uniform thickness on one or both surfaces of the fiber board-after whichthefiber board isbaked preferably by exposure to infra-redradiation. Finally the complete fiber board is sawed to desired dimension after which it is permitted to airdryfor several days.

Referring now to -the drawings; the apparatus employed in the production of the-fiber 'boards is preferably installed in a twostory; building; Located on the first floor of-the-buildingis a fibering machine indicated at -lll -in whichwood is reduced to a fibrous state? Machinessuitable for this purpose arereadily available and it will not be described-in detail. However, itmay be noted that preferably thewoodsupplied to the machine for fibering-is cut into eighteen inch-lengths: thus to a large degreepredetermining-the length of fibers produced.

Suitable means such for example asa blower (not shown) are provided-for blowing thefibers through aconduitll into atank l2 whichis located'on the second floor ofthe building. The tank l2 contains a solutionof commonsalt and the fibers are permitted to stand in'the sa'ltsolution until thoroughly impregnated. Thereafter, the fibers are removed fromthe salt -solution-in the tank l2 and the excess wateris permittedto drain off. The damp fibers are-thenplacedgin an elongated tank'l l which is provided -with'a plurality of rotating metal paddles indicated-generally at I5. overlying one end; of---the-tanl -l4 is a hopper It which contains dry Portland-cement which is sifted onto the fibers by suitable means such for example as aworm screw (not shown), drivenat a rate tosupply the appropriate amount of cement.

The paddles l5 rotatein the direction-of the arrow shown in'Figure 1 and have a dualpurpose. In" the first place, theyinsure thorough mi-xing of the dry cement with-the damp fibers-so that in effect each ofthe fibersis substantially; completely coated with cement. At the-same time the paddles advance-the fiber coated cement longitudinally ofthe tank l4.

At thedis charge end of the'tankl4--there is a downwardlyopening passage -l8 connecting to an inclined open topped chute 19. By the time the cement coated wood fibers reach the chute l9 they form a semi-fluid mass which may advance downwardly along the chute l9 by gravity, or if preferred the chute may include a conveyor for advancing the material at a predetermined rate downwardly along the chute.

Adjacent the chute are a plurality of work- In operation a workman is located at each of the stations -23. molds are provided and each of the work-'- men places a predetermined amount of cement coated fibers in a predetermined number of forms and assembles the forms in vertical stacks or tiers. Thus for example, inthe present em-' Open topped forms or sources of radiant heat.

bodiment of the invention illustrated it is con-j templated that four working stations will be provided and that at each station the workman will fill and stack five molds. When the workman at station 20 has completed filling and stacking five molds he pushes the stack of molds to the station 2| at which station the second workman fills and adds five more molds or forms to the stacks. This operation is continued until at station 23 the workman completes the stack of twenty forms by filling and adding five forms thereto. Thereafter the assembly of stacked forms is advanced to a press at which point sufiicient pressure is supplied to the assembly of forms to cause all of the forms to interfit as illustrated in Figure 3. It will be observed that each of the molds is adapted to interfit with the adjacent molds so that when sufiicient pressure is applied to bring each of the molds into engagement with the adjacent molds, the contents of the molds will be compressed to a uniform predetermined thickness. In practice it is contemplated that the forms will be of a size to produce fiber board having a thickness of one inch or three inches although of course any desired thickness of board may be produced by the selection of proper molds.

. After the assembly of molds has been compressed so as to bring each of the molds into contact with the adjacent molds, suitable means are provided to retain the assembly of stacked molds in compressed relationship. This means is illustrated in Figure 3 as comprising a plurality of rods having nuts 36 by means of which clamping members 31 may be secured together in the manner illustrated.

After the forms have been bound together they are removed from the press with a lift truck and are allowed to stand for at least twentyfours hours which permits the cement to set and causes the boards to reach a condition in which they will retain their shape.

Thereafter the boards are removed from the forms and are placed on a conveyor belt one at a time and a smooth coating of paste is applied to one side of the boards. This paste in its preferred form has solid constituents which are by weight approximately eighty-two per cent plaster, five per cent wheat paste, five per cent sugar, three per cent bentonite filler and five .permit trimming the boards.

4 per cent asbestos. The solid constituents are mixed with water to form a paste of a consistency suitable for spreading as by means of a doctor blade or the like. In practice the conveyor belt advances the board beneath the doctor blade which provides a predetermined coating of paste,

after which the same conveyor advances the boards through a tunnel with means therein for drying the coating hard enough so that the boards may be trimmed. heating means are provided in the tunnel and Preferably electric this means may conveniently take the form of The parts are constructed and arranged so that upon emergence from the tunnel the coating is hard enough to Thereafter the boards are'advanced to a trimming saw which cuts them to desired dimensions. Finally, after cutting the boards are stacked up to air dry for three or four days before use.

The drawings and the foregoing specification constitute a description of the improved composition wood panel and method and apparatus of making same in such full, clear, concise and exact terms as to enable any person skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What I claim as my invention is:

1. The method of making sheet material from a fluid mix which comprises advancing fiuid mix along an incline, advancing a form for receiving fluid mix substantially horizontally in a vertical plane substantially parallel to a vertical plane through the fluid mix traversing incline, during progress of such form lengthwise of the fluid mix incline adding successively thereon additional forms in stacked relationship, the height of the stack of forms thereby being increased as such stack progresses toward the higher end of the fluid mix incline, and prior to the addition of each form to the stack placing in each top form fiuidmix from such incline.

2. The method defined in claim 1, including advancing the stack of forms intermittently and supplying mix to the top form on the stack While the stack is stationary.

3. The method defined in claim 1, including adding a plurality of forms to the stack each time it is stopped during its progress lengthwise of the fluid mix incline.

' CARL BLE'CKO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 306,900 Christ Oct. 21, 1884 857,143 Zagelmeyer June 18, 1907 1,376,731, Ryan, May 3, 1921 1,744,309 Henderson Jan. 21, 1930 2,066,846 McNeil Jan. 5, 1937 2,096,326 Hengerer Oct. 19, 1937 2,271,443 Schuh Jan. 27, 1942 2,421,721 Smith et a1. June 3, 1947 

